Controversy continues as to whether aprotinin (Trasylol) is prothrombotic.
The recent discovery of the thrombin receptor family, known as the protease
-activated receptor family (PAR) has been essential in aiding our understan
ding of the mechanism of action of aprotinin. Our results show that aprotin
in has no effect on platelet aggregation induced by adrenaline, adenosine d
iphosphate, phorbol-12-myristate-13-acetate, collagen or PAR 1 agonist pept
ide. However, aprotinin inhibits thrombin-induced platelet activation as as
sessed by macroaggregation, microaggregation and platelet membrane calcium
flux, Aprotinin inhibits proteolytic activation of platelets, but platelets
can still be activated by non-proteolytic mechanisms.